1. Technical Field
The present invention pertains to target detection based on return or response signals from an electromagnetic transmission. In particular, the present invention pertains to discriminating targets within response signals from an area including a plurality of targets and illuminated by an electromagnetic transmission.
2. Discussion of Related Art
In order to detect target objects, an object or an area may be illuminated by an electromagnetic field. Electromagnetic signals are reflected from the object or area and received and processed to identify a target object. The scattered response or reflected signals typically exhibit a set of resonances (e.g., resonating frequencies, etc.) that may be represented by damped sinusoids or poles. This pattern is distinctive and may be used to identify the object. Several conventional mathematical techniques may be utilized to determine the parameters (e.g., frequencies, damping constants, etc.) of these sinusoids. For example, the Matrix Pencil Method (MPM) places sample data points from a waveform or response signal of interest within two matrices. The matrices are manipulated to provide pole parameters (e.g., frequencies, damping constants, etc.) as eigenvalues of a matrix equation. This technique is preferred since the technique provides greater stability and less sensitivity to noise relative to other techniques, such as Prony techniques.
When a desired target is part of a scene that includes several targets, the resulting scattering response contains poles from all objects in the illuminated scene, thereby hindering or preventing identification of the desired target.